Brick stacker



Jan.27, 1970 F. J. FEARNE ETAL BRICK STACKER 5 Sheets-Sheet l FiledFeb.14, 1967 y i M m mu 6 m W154 w 7 Ni U p 4 iww Jan. 27, 1970 F. J. PEARNEETAL 3,491,901

BRICK STACKER Filed Feb. 14, 1967 5 Sheets-Sheet 2 MATTORNEYs 2 7, 1970F, J, PEARNE ET AL 3,491,901

BRICK STACKER Filed Feb. 14. 1967 5 Sheets-Sheet 5 INVENTORSFGPEIV7YIVIJ ane/v5, ie/40K 5. ane/v6,

a 'MTTORNEYS Jan. 27, 1970 F. J. PEARNE ETAL 3,491,901

BRICK STACKER Filed Feb. 14, 1957 5 Sheets-Sheet 4 f? 4 ZZ m2 42 /2 A?4/ it a irjw /03 Jl /0 33 a l agi-P ill mm I I II [I 1 ll lllh I I BY MWf/VA/X FARF/A/GI'OM awn/5, 60mm M ATTORNEYS Jan. 27, 1970 F. J. PEARNEETAL 3,491,901

' BRICK STACKER Filed Feb. 14} 1967 5 Sheets-Sheet 5 MATTORNEYS UnitedStates Patent 3,491,901 BRICK STACKER Florenfin J. Pearne, Alhambra,Frank S. Pearne, San Gabriel, Frederick G. Robson, Long Beach, and JackR. Duncan, Corona, Calif., assignors to Pearne and Lacy Machine Company,Inc., Los Angeles, Calif., a corporation of California Filed Feb. 14,1967, Ser. No. 616,125 Int. Cl. B65g 57/20, 57/10; B65h 3/08 US. Cl.214-6 ABSTRACT OF THE DISCLOSURE An automatic brick stacking machine forforming stacks of bricks adapted to be subsequently strapped and tied inpackages suitable for the convenient storage, handling and shipping ofthe brick. The machine includes a conveyor which delivers the brick to astacking station adjacent to a vertically movable platform or elevator.A gripper transfer removes rows of brick each containing predeterminednumbers of brick from the conveyor and positions the rows on theelevator. The elevator is then lowered and succeeding rows are placed onthe preceding rows until a stack having the desired number of rows iformed. Separator sheets are automatically positioned between at leastsome of the rows as the stack is formed on the elevator. The grippertransfer provides predetermined rows with voids, so that spaces areprovided in the stack to receive the fork of a lift truck, or the like,so that the finished package can be handled with conventional materialhandling equipment. After the stack is formed on the elevator, a pushermoves the stack to a shuttle car which in turn delivers the stack to aconveyor along which the stack is moved to a strapping or tieing machine(not disclosed).

Field of invention This invention relates generally to machines forautomatically handling articles and more particularly to a machine forautomatically stacking bricks, or the like, so that they may be packagedfor convenient handling with conventional material handling machines.

Background of invention In the past it has been customary in manyinstances to store, ship, and otherwise handle the brick in a loosecondition. The handling of brick in a loose condition presents problemsof storage since large areas are required for the storage of the brick.Also, in such a procedure the brick are often damaged and the expense ofhandling is high.

In the co-pending application, Ser. No. 441,496, filed Mar. 22, 1965,now Patent Number 3,392,851, assigned to the assignee of the presentinvention, a machine is disclosed which is operable to automaticallyform stacks of bricks, or the like. These stacks are arranged so thatthey can be strapped and tied into unitary packages each containing alarge number of bricks. The packages are provided with voids adapted toreceive the fork of a lift truck or other material handling equipment,so that the package can be handled easily by conventional materialhandling equipment without requiring the use of pallets, skids, or thelike. The present application performs the same general function as thisco-pending application. However, the structure and function of theillustrated machine incorporating the present invention is simplified toreduce manufacturing costs, improve operating reliability and reduce themaintenance cost of the machine.

'9 Claims 3,491,901 Patented Jan. 27, 1970 Summary of invention In amachine incorporating the present invention a conveyor is provided whichdelivers brick to a stacking station in an abutting relationship. Avertically movable elevator or platform is located adjacent to theconveyor at the stacking station and a gripper transfer is providedwhich is operable to transfer rows of brick from the conveyor to theelevator. The gripper transfer grips the rows of brick on the conveyorand moves the rows laterally to a position over the elevator. The rowsare then released onto the elevator which then drops down so that asubsequent row can be positioned on the preceding row until a stack ofthe required height is formed.

The gripper transfer provides simplified gripping means for gripping thebrick and for moving the row of brick horizontally to the releaseposition over the elevator. The gripper transfer is arranged so thatvoids are automatically formed in predetermined rows by leaving selectedbricks on the conveyor for later transfer to the elevator. Because thetransfer of brick from the conveyor to the elevator is lateral withrespect to the conveyor it is not necessary to raise the gripped brickeven when rows containing voids are transferred.

A mechanism is also provided to position separator sheets between atleast some of the rows on the elevator during the stacking operation.The separator sheet trans fer mechanism utilizes vacuum both for thegripping of the top separator sheet in the supply stack, and for thepower source to move the gripped sheet into position on the elevator.Automatic sequencing of gripping and move ment of the separator sheetsis provided since the actuating vacuum does not build up until thevacuum gripping occurs.

As soon as the desired stack is formed on the elevator the entire stackis pushed onto a shuttle car which delivers the stack to the conveyorleading to the strapping machine. The transfer of the completed stackfrom the elevator to the shuttle car occurs as soon as the stack iscompleted to clear the elevator quickly so that the elevator is incondition to receive the subsequent stack.

Objects of invention It is an important object of this invention toprovide a novel and improved machine operable to form stacks of similararticles which are suitable for convenient handling and shipping.

It is another important object of this invention to provide a novel andimproved stacking machine arranged to automatically receive articlesfrom a conveyor or the like and form stacks of such articles wherein thestacks consist of a plurality of rows with each row containing aplurality of abutting articles and wherein voids are automaticallyformed in predetermined rows.

It is another important object of thisinvention to provide a novel andimproved stacking machine operable to form stacks consisting of rows ofblock-like articles wherein separator elements are automaticallypositioned between predetermined rows.

It is another important object of this invention to provide a stackingmachine for block-like articles including a novel and improved grippertransfer operable to grip rows of such articles and transfer such rowsfrom a conveyor to a stacking platform.

It is still another object of this invention to provide a machine forstacking block-like articles incorporating novel and improved means forpositioning separator elements between selected rows in the stack formedin the machine.

It is still another object of this invention to provide a machine forstacking block-like articles on a stacking platform wherein a novel andimproved combination is provided in which the stacks are transferred toa shuttle car for movement out of the machine so that the stackingplatform is immediately cleared to receive a subsequent stack.

It is still another object of this invention to provide a novel andimproved stacking machine for block-like articles including a stackconveyor operable to combine the stacks formed by the machine withstacks formed by similar machines and deliver the output of machines toa strapping or tieing machine.

Further objects and advantages will appear from the followingdescription and drawings, wherein:

FIGURE 1 is a schematic perspective view of a machine illustrating thegeneral arrangement of the principal sub-assemblies (in this figure someof the sub-assemblies have been moved from their proper positions sothat the structure can be better illustrated);

FIGURE 2 is a side elevation of the stacking machine;

FIGURE 3 is a plan view of the stacking machine;

FIGURE 4 is an end elevation of the stacking machine taken generallyalong 4-4 of FIGURE 2;

FIGURE 5 is an enlarged fragmentary end elevation of the grippertransfer;

FIGURE 6 is an enlarged fragmentary side elevation of the grippertransfer;

FIGURE 7 is an enlarged fragmentary side elevation in longitudinalsection of the separator sheet transfer actuator;

FIGURE 8 is an end elevation taken generally along 88 of FIGURE 2; and,

FIGURE 9 is an enlarged fragmentary side elevation of the shuttle car.

In all of the figures various structural elements have been eithercutaway or removed to provide a clearer illustration of the variousassemblies and sub-assemblies of the machine.

Referring to FIGURE 1, the illustrated embodiment of this machineincludes a power driven belt conveyor 10 which operates to deliver aline of abutting bricks to a stacking station 11. Located at thestacking station 11 is a gripper transfer assembly 12 which is operableto grip a row of bricks resting on the conveyor 10 and transfer suchbricks to a position over a vertically movable stacking platform 13.

The platform 13 is raised to a position immediately below the grippedrow of bricks when the first row of each stack is transferred.Therefore, such row drops only a small fraction of an inch when it isreleased by the gripper transfer 12. The platform 13 then automaticallylowers to position the upper surface of the row resting thereon in aplane immediately below the lower surface of the subsequent row ofbricks moved over the platform by the transfer assembly 12. The machineis arranged to operate through repeating cycles with the platform 13progressively lowering as rows are deposited thereon by the transferassembly 12 until a full stack of bricks having a predetermined numberof rows are positioned on the platform 13.

The gripper transfer 12 is arranged to automatically produce voids 15 inpredetermined rows in the stack 20. Normally the voids are formed in therow adjacent to the bottom row and are located and sized to receive thefork of a lift truck or other conventional material handling equipment.

A veneer board 14 is placed between the second and third rows to supportthe bricks above the voids 1S and chip boards 17 are positioned betweenthe other rows within the stack to protect the bricks within the rowsand to tie the stack together.

A board hopper 16 provides the supply of veneer boards 14 and chipboards 17. The hopper 16 is shiftable from a first position in which theveneer boards 14 are located under a transfer actuator 18 and a secondposition in which the chip boards are positioned under the transferactuator 18. The transfer actuator 18 is arranged to lift the top veneerboard 14 or chip board 17 from the board hopper 16 and automaticallycarry such board to a position over the top row resting on the platform13 and then release such board so that it rests on such top row. Theoperations of the gripper transfer assembly 12 and the transfer actuator18 are arranged so that the transfer actuator 18 performs its operationwhile the gripper transfer 12 is clear of the platform 13.

The machine is arranged to automatically operate through repeatingcycles until the required number of rows to form a complete stack arelocated on the platform 13. At that time, the platform 13 ishorizontally aligned with the bottom of a shuttle car 19. The pusher 21then operates to slide the entire stack from the platform 13 onto theshuttle car 19 thereby clearing the platform quickly so that it may beraised back up and a subsequent stack can be formed. While thesubsequent stack is being formed on the platform the shuttle car 19 ismoved longitudinally along rails 22 into alignment with a roller orslide plate conveyor 23 which is adapted to carry the completed stacksout of the machine to a strapping machine (not shown). A pusher 24operates to slide the stack from the shuttle car 19 onto the conveyor 23so that the shuttle car can return to receive the subsequent stack.

In some instances two or more similar stacking machines are located atspaced points along a single conveyor system so that the combined outputof the similar machines can feed to a single strapping machine. In suchmachines the stacks from the remote machine move along a roller or slideplate conveyor 26, across a roller or slide plate conveyor section 27,and along the conveyor 23 to the strapper. The conveyor section 27 iscarried by the shuttle car and is positioned, as illustrated, betweenthe conveyors 23 and 26 when the shuttle car is in the stack receivingposition.

Referring now to FIGURES 2 and 3, the belt conveyor 10 includes a drivepulley 28 at one end and a tensioning pulley 29 at the other end. Asuitable drive motor 31 is connected to drive the pulley 28. Tensioningscrews 32 provide adjustment of the tensioning of the belt. The upperreach 33 is supported along its length by an I-beam 34, best illustratedin FIGURE 8. The lower reach 36 is supported by spaced roller assemblies37.

Bricks are loaded onto the upper reach 33 of the conveyor 10 at anylocation remote from the stacking position 11. Any suitable means forloading of the conveyor can be used, however, it is preferable toprovide an automated power loading system for positioning the bricks onthe conveyor 10.

A stop assembly 38 is mounted adjacent to the stacking station and isprovided with a stop arm 39 extending over the upper reach 33 of theconveyor 10. The bricks are carried along the upper reach betweenlateral guides (not shown) until the stop arm 39 prevents furthermovement with the belt. This causes the bricks to form a row 52 ofabutting and aligned bricks at the stacking station 11. The stopassembly 38 is spring loaded against the bricks and is provided with aswitch which is operated when the force on the arm 39 is sufilcientlyhigh to indicate that the column of abutting bricks is at least as longas the row to be transferred. This switch is connected into the controlof the gripper transfer 12 to prevent operation of the gripper transferwhen insufficient bricks are located at the stacking station to form afull row for transfer by the gripper transfer assembly.

The gripper transfer assembly 12 is best illustrated in FIGURES 5 and 6.It includes a main carriage 41 supported by rollers 42 for reciprocatingmotion along track members 43 carried by the machine frame. The powerfor reciprocating the carriage 41 is provided by an actuator 44 mountedat one end on the frame of the machine and provided with a piston 46connected to the main carriage 41. Extension of the piston 46 moves themain carriage 41 to the position illustrated in FIGURE 6 wherein thegripper is located over the upper reach 33 of the conveyor and theretraction of the piston 46 moves the gripper mechanism to a positionover the vertically movable platform 13.

A pivoted carriage 47 is pivotally mounted at 48 on the main carriage 41and is operated between a lowered operative position illustrated inFIGURES 5 and 6 and a raised position illustrated in phantom in FIGURE 6by a piston and cylinder actuator 49 connected between the main carriage41 and the pivoted carriage 47. The pivoted carriage 47 is provided witha fixed depending flange 51 which extends down beside the line of bricks52 on the upper reach 33 remote from the platform 13 when the pivotedcarriage 47 is in the operative position illustrated. Gripping pads 53are mounted on the flange 51 and are positioned to engage and grip oneend face of the bricks in the line 52.

A movable gripping element 54 is carried by a swinging frame 56 mountedon the pivot frame 47 by parallelogram links 57. An actuator 58 isconnected between the pivot frame 47 and the swinging frame 56 and isoperable to move the swinging frame between the gripping positionillustrated in FIGURE 6 and a retracted position illustrated in FIGURE4. The gripping element 54 is a resilient tubular element which iscompressed against the adjacent end face of the row of bricks 52 whenthe swinging frame 56 is in the clamping position of FIGURE 6. Thegripping element 54 therefore compensates for variations in the lengthof the individual bricks and insures proper gripping of all of the brickin a row to be transferred.

Voids are automatically provided in selected rows of bricks so that thefinished stack can be handled by the fork of the lift truck or the like.In order to provide such voids the flange 51 is formed with two spacedopenings 61, best illustrated in FIGURE 5, which are normally closed bypivoted doors 62. The doors 62 are pivoted on the flange 51 for rotationabout the pivot 63. An actuator 64 is connected between the pivotcarriage 47 and an arm 66 and is operable to pivot the doors 62 to theclosed position illustrated or to the horizontal position above the rowof bricks 52. The doors 62 are provided with gripper pads 53 whichcooperate with the gripper pads 53 on the flange 51 when the doors areclosed to engage each brick in the row to be transferred. In theillustrated embodiment, when the doors 62 are open, two bricks in therow at each door, as indicated at S in FIG- URE 5, remain ungripped andwhen the transfer assembly is operated such bricks remain on theconveyor leaving the desired spaces in the transfer row. When voids areto be formed a stop 72 is raised by an actuator 71 to hold the bricks Sagainst movement with the gripped bricks. When voids of different sizesare required the size of the doors 62 and the size of the stops arechanged to provide the proper size of void.

- The operation of the gripper transfer 12 is as follows.

The cycle begins when the elements are in the position of FIGURE 4. Atthis point in the cycle of operation the actuators 44, 49 and 58 areextended. If the row to be transferred does not require voids, theactuator 64 is retracted to close the doors 62. As soon as the stop arm39 indicates that suflicient bricks are present in the row 52 and assoon as the other portions of the machine controls indicate thattransfer can be made, the two actuators 44 and 58 are operated in aretraction direction. This brings the gripper pad 53 into engagementwith one side and the gripper element 54 into engagement with the otherside of the row of bricks. The gripping is completed when the elementsreach the position of FIGURE 6.

Continued retraction of the actuator 44 causes the fourteen bricks tothe left of the point 67 in FIGURE 5 to be carried to the left as viewedin FIGURE 6 across a fixed table 68 to a position immediately above theveneer board 14 on the row 69 previously set on the platform 13. In thisinstance the row 69 is the row with voids. When the row carried by thegripper transfer is properly positioned above the platform 13 and anypreceding rows resting thereon, the actuator 58 is extended to releasethe gripping of the row and the actuator 49 is retracted to raise thegrippers up clear of the row. At this point in the operation, theactuator 44 extends to move the gripper transfer assembly back to itspick-up position and the platform 13 lowers to again position the top ofthe uppermost row in the proper position to receive a separator boardand a subsequent row. When the actuator 44 is extended so that theflange 51 is past the row 52 the actuator 49 extends, returning theelements to the position of FIGURE 4 for recycling.

In the event that a row having voids therein is to be transferred, theactuator 64 is retracted and the stop plate actuator 71 is actuated toraise a stop plate 72. The stop plate is proportioned to block only thebricks which remain ungripped and prevent their being dragged along withthe gripped row. Aside from the operation of these two actuators thecycle is the same and in the illustrated embodiment ten bricks aretransferred leaving two voids in the transfer row.

The platform 13 is mounted on the piston 73 of an elevator actuator 74so that it is vertically movable between fixed guiding side plates 76between an uppermost position in which the upper surface of the platform13 is substantially aligned with the table 68 and a lowermost positionin which the upper surface of the platform 13 is aligned with the bottomof the shuttle car 19.

The structure and the operation of the separator board actuator 18 canbest be understood by referring to FIG- URES 1, 7 and 8. The boardhopper 16 is mounted at opposite ends on parallelogram links 81 whichare pivoted at their upper ends on a frame member 82 and on their lowerends on extensions of the hopper 16. An actuator 83 is connected toreciprocate the hopper 16 between a first position wherein the actuator18 is over the chip boards 17 and a second position in which theactuator 18 is over the veneer boards 14. The hopper itself is dividedinto two chambers one of which is supplied with chip boards and theother of which is supplied with veneer boards. The bottom of eachchamber is provided by a vertically movable plate 84 (see FIGURE 8)supported on the piston of an associated actuator 86. The actuators 86are arranged to extend to bring the uppermost chip board or veneer boardin the associated section of the hopper 16 into engagement with a vacuumnozzle 87 on the actuator 18. As the chip boards and veneer boards areused the actuators 86 extend until the supply of the associated boardsis exhausted.

The structure of the transfer actuator 18 is best illustrated in FIGURE7. This actuator includes a cylinder 88 mounted on the frame of themachine by support members 89. A tubular piston 91 is reciprocable inthe cylinder 88 and is provided with a piston head assembly 92 at itsinner end. Projecting downwardly from the outer end of the piston 91 isa tubular guide 93 which telescopes into a vacuum pick-up assembly 94.

The vacuum pick-up assembly 94 is vertically movable along the tube 93between an extended position illustrated in FIGURE 7 and an upperposition wherein its upper end is adjacent to the outer end of thepiston 91. A guide pin 96 assists in guiding the vacuum pick-upassembly. A rubber pick-up cup 87 is mounted on the lower end of theassembly 94 along with a valve seat 97. A lightweight check valve 98 istrapped between the valve seat 97 and an apertured retainer 99 mountedin the lower end of the tube 93. Vacuum or pressure can be selectivelyprovided to the cylinder 88 through a port 101 from a motor driven fan102 and a control valve 103. When pressure is supplied to the port 101the piston assembly 92 carries the piston 91 to the right or retractedextreme position illustrated. This pressure is carried into the tubularpiston through ports 104, so pressure is present in the vacuum pick-upassembly 94 causing the check valve 98 to seal against the seat 97.

When a separator board is to be gripped and transferred the valve 103 isoperated to supply vacuum to the actuator through the port 101. Whenthis occurs the check valve 98 is lifted from its seat and the topmostchip board or veneer board is gripped by vacuum. The vacuum then causesthe vacuum pick-up assembly 94 to telescope upwardly to lift theuppermost board clear of the hopper 16 so it may be transferred to aposition over the row on the platform 13. When the vacuum pick-upassembly 94 reaches its uppermost position the vacuum in the cylinder 88builds up to a higher level and the piston cornmences to extend to carrythe vacuum gripped board to a position over the uppermost row on theplatform 13. The various controls are arranged so that the vacuum isapplied to the actuator 18 before the gripper transfer assembly .12moves back to its pick-up position. This in-' sures that the minimumtime will be required for the complete extension of the chip boardactuator 18. A roller stop 106 on the piston 91 engages a stop bar 107carried by the main carriage 41 of the gripper transfer assembly 12 ifthe gripper transfer is still in the release position when the actuator18 starts to extend. This holds the actuator against extension until thegripper transfer 12 moves clear of the actuator 18. Therefore, theactuator 18 extends to its fully extended position as soon as thegripper transfer 12 is clear of its release position above the elevator13. Therefore, a separator board is carried to a position over the rowon the elevator as soon as possible.

As soon as the actuator is in the full extended position it ispressurized by the valve 103 so that the board is released onto the rowof brick. The vacuum pick-up assembly 94 extends to guide the board toits proper position. The valve 98 seats at this time, so pressure canbuild up to a value sufficient to cause the piston 91 to again retractto a position over the board hopper. The raising of the vacuum pick-upassembly 94 raises the separator above the upper surface of the top rowof bricks so that the board can be positioned before the platform 13lowers.

The usual practice is to arrange the controls of the actuators 83 and 86so that a veneer board is deposited on the row of bricks having voidstherein and chip boards 17 are positioned on other rows within the stackas it is formed. The controls may be arranged so that chip boards areplaced on all of the rows or, if desired, so that chip boards are onlyplaced on selected rows to provide tying of the stack.

When the stack is fully formed the platform 13 is flush with the bottomof the shuttle car 19 as illustrated in FIGURE 4. The pusher 21 iscarried by a guide bar 108 which extends through spaced rollers 109 sothat the pusher plate 21 is supported for horizontal reciprocationbetween the retracted position illustrated and an extended positionwherein the pusher 21 slides the stack onto the shuttle car 19. Anactuator 111 provides the power for operating the pusher 21. Astationary plate 112 is mounted on the machine frame adjacent to theside of the shuttle car 19 to stabilize the stack as the pusher 21extends to push the stack onto the shuttle car. The shuttle car is alsoprovided with side plates 113 which cooperate to support the stack onthe shuttle car.

An actuator 114 is connected to move the shuttle car between thereceiving position adjacent to the elevator platform 13 and a deliveryposition in alignment with the roller conveyor 23. When the shuttle caris in the delivery position the pusher 24 is operated to push the stackoff of the shuttle car onto the conveyor 23 for delivery to the tieingmachine (not illustrated). The roller conveyor 23 may be of the typeillustrated in the copending application Ser. No. 441,496 cited above.

The power for operating the pusher 24 is provided by motors 116 and 119which are connected to drive a chain 117. The chain 117 is connected toreciprocate a carriage 118 on which the pusher 24 is mounted. The motor116 provides relatively high thrust at a relatively low pusher speed andthe second motor 119 provides higher pusher speed but lower thrust. Whena single machine is used to feed a single strapper only the high thrustmotor 116 is used since the pusher operating distance is small and highthrust is required to move the stack into proper position in thestrapper. However, when two machines are used to supply a singlestrapper the high speed motor 119 is used to rapidly push the stackalong the conveyor 26 and then the high thrust low speed motor 116 isoperated to complete the pushing of the stack into the strapper. The twomotors 116 and 119 illustrated are hydraulic and the control valves arearranged so that the slow speed motor merely recirculates fluid when thehigh speed motor is powering the pusher.

Operation The operation of the machine is as follows. Bricks are carriedalong the conveyor 10 to form a row 52 against the stop member 39, asbest illustrated in FIGURE 5. The gripper transfer assembly 12 thenoperates to grip a row of bricks from the line 52 and carries such rowto a position over the elevator platform 13. The row is then releasedand the gripper transfer returns to its pickup position to pick-up asubsequent row. The elevator is automatically lowered so that theuppermost row resting thereon is properly positioned to receive thesubsequent row.

The transfer actuator 18 operates to position a separator board of theappropriate type on the row while the elevator is dropping. The use ofthe vertically movable vacuum pick-up assembly 94 raises the separatorboard high enough so that it may be positioned on the row even beforethe topmost row is lowered to the receiving position. By providinsimultaneous operation higher speeds can be achieved. Appropriate voidsare formed in the stack at the desired locations and veneer boards 14are placed over the rows with voids so that suflicient strength will beprovided to support the subsequent rows.

When the stack is completed the pusher 21 is operated to slide the stackonto the shuttle car and is retracted so that the platform 13 can beraised immediately to receive a subsequent row. The shuttle car is thenmoved to the delivery position while the subsequent stack is beingformed and the pusher 24 slides the stack off of the shuttle car ontothe conveyor for delivery to the strapping machine. When two or moremachines are provided to feed a single tieing machine or strapper thecontrols for the pushers 24 and shuttle cars 19 are interconnected toinsure that one stack will not interfere with the movement of anotherstack and so that the pusher is properly positioned before the shuttlecar moves to its delivery position.

The various sub-assemblies are arranged to operate simultaneouslywhenever possible so that the cycle time of the machine may bemaintained as short as possible. For example, the row 52 of bricks iscarried to the stacking position while the transfer gripper is carryingthe preceding row to a position over the platform 13 so that asubsequent row can be gripped as soon as the gripper transfer returns tothe gripping position. The separator board actuator 18 partially extendsbefore the gripper transfer returns to its pick-up position so that aminimum time is required for the placing of the separator board on thetop row. Also, the placement of the separator board may occur while theelevator 13 is lowering. Consequently, the chip board transfer actuator18 can be retracted clear of the elevator 13 almost as soon as theelevator reaches its lowered receiving position for the subsequent row.

The use of a shuttle car permits the unloading of the elevator 13 so asubsequent stack can be formed as soon as possible. Further, the shuttlecar and freeway pusher 24 permit the machine to be operated inconjunction with a similar adjacent machine so that two or more similarmachines can be operated to supply a single strapping machine.

Suitable control switches are connected to the controls of the variousactuators and are located to sense the related operations so that propersequencing is assured. In some cases photoelectric cells are used todetermine the position of elements. For example, a photoelectric celldetermines the proper position of the upper surface of the topmost rowon the platform 13. The various actuators may be either hydraulic orpneumatic and the various rotary motors may be either electric,pneumatic, or hydraulic, depending upon the type of power available in aparticular installation.

Although a preferred embodiment of this invention is illustrated, it isto be understood that various modifications and rearrangements of partsmay be resorted to without departing from the scope of the inventiondisclosed herein.

We claim:

1 A machine for stacking rows of similar articles in superposedrelationship wherein said rows have a predetermined length comprising astop, gathering means operable to form a line of abutting alignedarticles against said stop and extending in one direction therefrom,said line having a length at least equal to the length of said rows, aplatform laterally positioned beside a line formed on said gatheringmeans, a transfer carriage, power operated grippers on said carriage,said carriage being movable with substantially straight-line movementbetween a gripping position in which said grippers are in position togrip articles in said line and a release position in which said grippersare in said position to release articles over said platform, saidgrippers being operable to individually grip and support articles insaid line so that the gripped articles constitute one of said rows ofsaid predetermined length, said carriage and grippers being operable togrip said article on said gathering means and to directly move saidarticles to a position over said platform along a substantiallystraight-line path, said grippers being operable to release said rowwhile said carriage is in said release position, said platform beingoperable to a lower position after a row is placed thereon so that theupper surface of the uppermost row thereon is spaced below the plane ofthe lower surface of a subsequent row being transferred thereto by saidgrippers so that a subsequent row may be positioned on a preceding row,said grippers being operable to place said subsequent row directly'onsaid preceding row in superposed relation, said grippers includingportions intermediate the ends of the grippers movable between anoperative position in which they grip selected articles intermediate theends of the line of articles and a retracted position clear of saidselected articles to leave selected articles intermediate the ends ofselected rows on said gathering means when said carriage is moved tosaid release position, said gathering means being operable to move saidselected articles toward said stop to incorporate such selected articlesin a subsequent line.

2. A machine as set forth in claim 1 wherein means are provided to movean entire stack of rows off said platform when a stack consisting of apredetermined number of rows is on said platform.

3. A machine as set forth in claim 1 wherein blocking means movablebetween a blocking position and a retracted position are provided toretain said ungripped articles on said conveyor.

4. A machine as set forth in claim 3 wherein said gripping meansincludes opposed gripping elements, and one gripping element includessections movable to a retracted position clear of said articles to leavesaid ungripped articles on said conveyor.

5. A machine as set forth in claim 1 wherein at least two opposedgripping elements are provided and at least one element is powered formovement toward and away from the other element for gripping and releaseof said articles.

6. A machine as set forth in claim 1 wherein a separator board transferis provided to position separator boards on rows resting on saidplatform.

7. A machine for stacking block-like articles comprising a conveyoroperable to form a line of abutting aligned articles, a platform spacedfrom said line, and article transfer means operable to stack rows ofarticles by moving in a substantially straight line between a pickupposition at said conveyor in which it grips a row of articles and adelivery position at said platform in which it positions said row onsaid platform, a supply of separator boards, and a separator boardtransfer operable to remove a separator board from said supply andposition such board on said row, said separator board transfer operatingto commence movement of said separator board toward said row before saidarticle transfer means moves clear of said platform, said articletransfer means and separator transfer being provided with interengagingstop means operable to prevent completion of the movement of saidseparator board transfer toward said row until said article transfer isclear of said platform.

8. A machine for stacking rows of similar articles as set forth in claim1 wherein said gathering means is a horizontally extending conveyor,said substantially straight-line of movement being substantiallyhorizontal and substantially perpendicular to the length of saidconveyor.

9. A machine as set forth in claim 1 wherein said grippers include onegripper element which is substantially fixed with respect to saidcarriage and a second gripper element which is movable toward and awayfrom said one gripper element, said second gripper element being movableto a raised position above said line while said carriage moves from saidreleased position to said gripping position.

References Cited UNITED STATES PATENTS 2,95 6,3 81 10/ 1960 Chauuin etal. 3,388,815 6/1968 Lingl. 3,392,851 7/1968 Pearne et al. 3,404,788 10/1968 Thomas et al.

732,221 6/ 1903 Potuin. 2,710,696 6/ 1955 Fontaine et al. 2,883,0744/1959 Boehl et al. 2,933,207 4/1960 Edmonds et al. 3,262,594 7/1966Teago 214652 3,270,897 9/ 1966 Lingl.

FOREIGN PATENTS 914,957 1/ 1963 Great Britain.

GERALD M. FORLENZA, Primary Examiner ROBERT J. SPAR, Assistant ExaminerUS Cl. X.R. 29462, 103

